1. Field of the Invention
The present invention relates to a machine tool provided with a wiper in a table on which a workpiece is placed as means for removing chips deposited on a movable cover.
2. Description of the Related Art
In a machine tool with a splash guard covering the working region in order to prevent chips generated during working from scattering to outside the machine tool, chips deposit on a telescopic cover fixed to a table and adhere to the surface of the telescopic cover. As disclosed in Japanese Patent Application Laid-Open No. 2001-150291, for example, as a conventional technique to cope with this situation, there is generally known a method in which a wiper is fixed to one of a plurality of members constituting a telescopic cover capable of expanding and contracting and the wiper is brought into contact with the surface of the telescopic over, whereby chips are removed in the longitudinal direction of the telescopic cover during the movement of the table. In addition, Japanese Patent Application Laid-Open No. 11-277363 discloses a method which involves scraping down chips deposited on telescopic covers in synchronization with the opening and closing of a door.
The technique disclosed in Japanese Patent Application Laid-Open No. 2001-150291 mentioned above has a problem of the accuracy of the machine tool being affected by the sliding resistance between the telescopic cover and the wiper when the table moves. In the technique disclosed in Japanese Patent Application Laid-Open No. 11-277363 mentioned above, chips deposited on a telescopic cover in front of a table are scraped down during the opening and closing of a door. Accordingly, when the working had taken time and the door had not been opened and closed for a long time, chips would continue to deposit, adversely affecting the action of the cover. However, no description is given of a solution to this. Furthermore, for the deposition of chips onto a telescopic cover at the rear of the table, how to cope with this is not taken into consideration.